Among other things, the line between online and local to your computer has been blurred quite a bit. Before all this JavaScript tracking became common, the only

Among other things, the line between online and local to your computer has been blurred quite a bit. Before all this JavaScript tracking became common, the only information a website would get when you visited a page was... the page you loaded and the IP you loaded it from. A third-party may have gotten similar information if there are embedded resources. Now, though, thanks to client-side analytics, that website and any of those third parties may be recording your mouse movements, checking to see how long you stay on the page, fingerprinting you based on what addons/fonts you have and what your screen size is, etc. It's more than just on the web. If you took a photo on a camera, it stayed on the camera. If you take a photo on your phone... is cloud sync enabled? Because it might be by default. I was pretty shocked at how pushy the preloaded apps were when I recently bought a budget Android phone.